Ive recently been using some brushes with the Pur Tech synthetic knots from Virginia Sheng; I havent seen much here about them, so I thought Id share some observations. Let me say first that my experience with synthetics is limited, and I havent tried any of the higher end stuff like Muhle or Plisson, so I cant make those direct comparisons. Lacking that context, I will just say that Ive been very impressed with both the performance and, especially, the value offered by these knots.
The first thing that is apparent is that the Pur Tech has exceptionally soft tips, softer than most silver tip knots Ive felt. It feels terrific when face lathering. Despite this softness, it also has good backbone, and picks up hard soaps surprisingly well. It does have the synthetic spring back character, which I know some dont care for, but thats pretty much inherent in any synthetic. I find that it generates and holds lather very well; plenty for my regular two-pass-plus-touch-ups routine, even the smaller 20mm knot.
At this point, Ive only used these knots for restorations, but both knots and finished brushes are available from VS. The knots are available at pretty amazing prices; generally about $10-$12 shipped. Though the finished brushes look to be set in very basic (aka cheap) plastic handles, they are, if anything, an even better deal than the knots.
You do have to be willing to wait on the slow boat from China to get these, but so far my dealings with VS have been good and shipping times have been reasonable. I find the wait worth it for these high value brushes. Whether you already like synthetics, or have been looking to give one a try, the Pur Tech is a great option, and the outlay risk is low. Im really happy with mine.
Have fun.
